Resistance of weeds to herbicides that were initially controlled by that herbicide has increased in all major crops and forages. An internet web site, http//weedscience.com, logs all confirmed resistant weed species and their location by country. Management of these species and the cost of those management techniques was the focus of this symposium. The group of scientists assembled for this symposium were chosen to discuss the systems currently utilized in the management of species that are resistant to a single or to multiple groups of herbicides. It is hoped that information presented on the cost of managing these resistant species will further encourage the judicious use of herbicides, the implementation of agronomic practices, and crop rotations to delay the development of resistance to other areas.